Using multiple signals to detect touch input
Detecting a location of a touch input is disclosed. Each of a plurality of transmitters coupled to a propagating medium emits a signal that is distinguishable from other signals emitted from other transmitters. The signals from the transmitters are received from at least one receiver coupled to the propagating medium to detect the location of the touch input on a surface of the propagating medium as indicated by an effect of the touch input on each of the distinguishable signals.
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This application is a continuation in part of co-pending U.S. patent application Ser. No. 13/451,288 entitled METHOD AND APPARATUS FOR ACTIVE ULTRASONIC TOUCH DEVICES filed Apr. 19, 2012, which is incorporated herein by reference for all purposes, which claims priority to U.S. Provisional Application No. 61/479,331, entitled METHOD AND APPARATUS FOR ACTIVE ULTRASONIC TOUCH DEVICES filed Apr. 26, 2011 which is incorporated herein by reference for all purposes.
BACKGROUND OF THE INVENTIONVarious technologies have been used to detect a touch input on a display area. The most popular technologies today include capacitive and resistive touch detection technology. Using resistive touch technology, often a glass panel is coated with multiple conductive layers that register touches when physical pressure is applied to the layers to force the layers to make physical contact. Using capacitive touch technology, often a glass panel is coated with material that can hold an electrical charge sensitive to a human finger. By detecting the change in the electrical charge due to a touch, a touch location can be detected. However, with resistive and capacitive touch detection technologies, the glass screen is required to be coated with a material that reduces the clarity of the glass screen. Additionally, because the entire glass screen is required to be coated with a material, manufacturing and component costs can become prohibitively expensive as larger screens are desired.
Another type of touch detection technology includes bending wave technology. One example includes the Elo Touch Systems Acoustic Pulse Recognition, commonly called APR, manufactured by Elo Touch Systems of 301 Constitution Drive, Menlo Park, Calif. 94025. The APR system includes transducers attached to the edges of a touchscreen glass that pick up the sound emitted on the glass due to a touch. However, the surface glass may pick up other external sounds and vibrations that reduce the accuracy and effectiveness of the APR system to efficiently detect a touch input. Another example includes the Surface Acoustic Wave-based technology, commonly called SAW, such as the Elo IntelliTouch Plus™ of Elo Touch Systems. The SAW technology sends ultrasonic waves in a guided pattern using reflectors on the touch screen to detect a touch. However, sending the ultrasonic waves in the guided pattern increases costs and may be difficult to achieve. Detecting additional types of inputs, such as multi-touch inputs, may not be possible or may be difficult using SAW or APR technology. Therefore there exists a need for a better way to detect an input on a surface.
Various embodiments of the invention are disclosed in the following detailed description and the accompanying drawings.
The invention can be implemented in numerous ways, including as a process; an apparatus; a system; a composition of matter; a computer program product embodied on a computer readable storage medium; and/or a processor, such as a processor configured to execute instructions stored on and/or provided by a memory coupled to the processor. In this specification, these implementations, or any other form that the invention may take, may be referred to as techniques. In general, the order of the steps of disclosed processes may be altered within the scope of the invention. Unless stated otherwise, a component such as a processor or a memory described as being configured to perform a task may be implemented as a general component that is temporarily configured to perform the task at a given time or a specific component that is manufactured to perform the task. As used herein, the term ‘processor’ refers to one or more devices, circuits, and/or processing cores configured to process data, such as computer program instructions.
A detailed description of one or more embodiments of the invention is provided below along with accompanying figures that illustrate the principles of the invention. The invention is described in connection with such embodiments, but the invention is not limited to any embodiment. The scope of the invention is limited only by the claims and the invention encompasses numerous alternatives, modifications and equivalents. Numerous specific details are set forth in the following description in order to provide a thorough understanding of the invention. These details are provided for the purpose of example and the invention may be practiced according to the claims without some or all of these specific details. For the purpose of clarity, technical material that is known in the technical fields related to the invention has not been described in detail so that the invention is not unnecessarily obscured.
Detecting a location of a touch input is disclosed. For example, a user touch input on a glass surface of a display screen is detected. In some embodiments, a plurality of transmitters coupled to a propagating medium (e.g., glass) emits signals that are distinguishable from other signals emitted from other transmitters. For example, a signal such as an acoustic or ultrasonic signal is propagated freely through a propagating medium with a touch input surface from each transmitter coupled to the propagating medium. In some embodiments, the signals emitted by the transmitters are distinguishable from each other by varying a phase of the signals (e.g., code division multiplexing, code division multiple access (CDMA), spread spectrum multiple access (SSMA)), a frequency range of the signals (e.g., frequency division multiplexing, frequency division multiple access (FDMA)) or a timing of the signals (e.g., time division multiplexing, time division multiple access (TDMA)).
At least one receiver is coupled to the propagating medium, and the receiver is configured to receive the signals from the transmitters to detect the location of the touch input on a surface of the propagating medium as indicated by the effect of the touch input on each of the distinguishable signals. For example, when the surface of the propagating medium is touched, the emitted signals propagating through the propagating medium are disturbed (e.g., the touch causes an interference with the propagated signals). In some embodiments, by processing the received signals and comparing it against corresponding expected signals without the disturbance, a location on the surface associated with the touch input is at least in part determined. For example, a relative time difference between when the disturbance was detected in the received signals is used to determine the touch input location on the surface. In various embodiments, the touch input includes a physical contact to a surface using a human finger, pen, pointer, stylus, and/or any other body parts or objects that can be used to contact or disturb the surface. In some embodiments, the touch input includes an input gesture and/or a multi-touch input.
In some embodiments, the received signal is used to determine one or more of the following associated with a touch input: a gesture, a coordinate position, a time, a time frame, a direction, a velocity, a force magnitude, a proximity magnitude, a pressure, a size, and other measurable or derived parameters. In some embodiments, by detecting disturbances of a freely propagated signal, touch input detection technology can be applied to larger surface regions with less or no additional cost due to a larger surface region as compared to certain previous touch detection technologies. Additionally, the optical transparency of a touch screen may not have to be affected as compared to resistive and capacitive touch technologies. Merely by way of example, the touch detection described herein can be applied to a variety of objects such as a kiosk, an ATM, a computing device, an entertainment device, a digital signage apparatus, a cell phone, a tablet computer, a point of sale terminal, a food and restaurant apparatus, a gaming device, a casino game and application, a piece of furniture, a vehicle, an industrial application, a financial application, a medical device, an appliance, and any other objects or devices having surfaces.
Examples of transmitters 104, 106, 108, and 110 include piezoelectric transducers, electromagnetic transducers, transmitters, sensors, and/or any other transmitters and transducers capable of propagating a signal through medium 102. Examples of sensors 112, 114, 116, and 118 include piezoelectric transducers, electromagnetic transducers, laser vibrometer transmitters, and/or any other sensors and transducers capable of detecting a signal on medium 102. In some embodiments, the transmitters and sensors shown in
Touch detector 120 is connected to the transmitters and sensors shown in
A signal detected from a sensor such as sensor 112 of
At 304, signal transmitters and sensors are calibrated. In some embodiments, calibrating the transmitter includes calibrating a characteristic of a signal driver and/or transmitter (e.g., strength). In some embodiments, calibrating the sensor includes calibrating a characteristic of a sensor (e.g., sensitivity). In some embodiments, the calibration of 304 is performed to optimize the coverage and improve signal-to-noise transmission/detection of a signal (e.g., acoustic or ultrasonic) to be propagated through a medium and/or a disturbance to be detected. For example, one or more components of the system of
At 306, surface disturbance detection is calibrated. In some embodiments, a test signal is propagated through a medium such as medium 102 of
At 308, a validation of a touch detection system is performed. For example, the system of
In some embodiments, sending the signal includes determining the signal to be transmitted by a transmitter such that the signal is distinguishable from other signal(s) transmitted by other transmitters. In some embodiments, sending the signal includes determining a phase of the signal to be transmitted (e.g., utilize code division multiplexing/CDMA). For example, an offset within a pseudorandom binary sequence to be transmitted is determined. In this example, each transmitter (e.g., transmitters 104, 106, 108, and 110 of
In some embodiments, sending the signal includes determining a frequency of the signal to be transmitted (e.g., utilize frequency division multiplexing/FDMA). For example, a frequency range to be utilized for the signal is determined. In this example, each transmitter (e.g., transmitters 104, 106, 108, and 110 of
In some embodiments, sending the signal includes determining a timing of the signal to be transmitted (e.g., utilize time division multiplexing/TDMA). For example, a time when the signal should be transmitted is determined. In this example, each transmitter (e.g., transmitters 104, 106, 108, and 110 of
At 404, the active signal that has been disturbed by a disturbance of the surface region is received. The disturbance may be associated with a user touch indication. In some embodiments, the disturbance causes the active signal that is propagating through a medium to be attenuated and/or delayed. In some embodiments, the disturbance in a selected portion of the active signal corresponds to a location on the surface that has been indicated (e.g., touched) by a user.
At 406, the received signal is processed to at least in part determine a location associated with the disturbance. In some embodiments, determining the location includes extracting a desired signal from the received signal at least in part by removing or reducing undesired components of the received signal such as disturbances caused by extraneous noise and vibrations not useful in detecting a touch input. In some embodiments, components of the received signal associated with different signals of different transmitters are separated. For example, different signals originating from different transmitters are isolated from other signals of other transmitters for individual processing. In some embodiments, determining the location includes comparing at least a portion of the received signal (e.g., signal component from a single transmitter) to a reference signal (e.g., reference signal corresponding to the transmitter signal) that has not been affected by the disturbance. The result of the comparison may be used with a result of other comparisons performed using the reference signal and other signal(s) received at a plurality of sensors. The location, in some embodiments, is a location (e.g., a location coordinate) on the surface region where a user has provided a touch input. In addition to determining the location, one or more of the following information associated with the disturbance may be determined at 406: a gesture, simultaneous user indications (e.g., multi-touch input), a time, a status, a direction, a velocity, a force magnitude, a proximity magnitude, a pressure, a size, and other measurable or derived information. In some embodiments, the location is not determined at 406 if a location cannot be determined using the received signal and/or the disturbance is determined to be not associated with a user input. Information determined at 406 may be provided and/or outputted.
Although
At 502, a received signal is conditioned. In some embodiments, the received signal is a signal including a pseudorandom binary sequence that has been freely propagated through a medium with a surface that can be used to receive a user input. For example, the received signal is the signal that has been received at 404 of
At 504, an analog to digital signal conversion is performed on the signal that has been conditioned at 502. In various embodiments, any number of standard analog to digital signal converters may be used. The resulting digital signal is used to perform a first correlation at 506. In some embodiments, components of the received signal associated with different signals/transmitters are separated. For example, different signals originating from different transmitters are isolated from other signals of other transmitters. In some embodiments, performing the first correlation includes correlating at least a portion of the converted signal (e.g., signal component from a single transmitter) with a reference signal (e.g., corresponding reference signal of the signal transmitter signal). Performing the correlation includes cross-correlating or determining a convolution (e.g., interferometry) of the converted signal with a reference signal to measure the similarity of the two signals, as a time-lag is applied to one of the signals. By performing the correlation, the location of a portion of the converted signal that most corresponds to the reference signal can be located. For example, a result of the correlation can be plotted as a graph of time within the received and converted signal (e.g., time-lag between the signals) vs. a measure of similarity. The associated time value of the largest value of the measure of similarity corresponds to the location where the two signals most correspond. By comparing this measured time value against a reference time value (e.g., at 306 of
At 508, a second correlation is performed based on a result of the first correlation. Performing the second correlation includes correlating (e.g., cross-correlation or convolution similar to step 506) at least a portion of the converted signal in 504 with a second reference signal. The second reference signal is a more complex/detailed (e.g., more computationally intensive) reference signal as compared to the first reference signal used in 506. In some embodiments, the second correlation is performed in 508 because using the second reference signal in 506 may be too computationally intensive for the time interval required to be correlated in 506. Performing the second correlation based on the result of the first correlation includes using one or more time values determined as a result of the first correlation. For example, using a result of the first correlation, a range of likely time values (e.g., time-lag) that most correlate between the received signal and the first reference signal is determined and the second correlation is performed using the second reference signal only across the determined range of time values to fine tune and determine the time value that most corresponds to where the second reference signal (and, by association, also the first reference signal) matched the received signal. In various embodiments, the first and second correlations have been used to determine a portion within the received signal that corresponds to a disturbance caused by a touch input at a location on a surface of a propagating medium. In other embodiments, the second correlation is optional. For example, only a single correlation step is performed.
At 510, a result of the second correlation is used to at least in part determine a location associated with a disturbance. In some embodiments, determining the location includes comparing a determined time value where the signals of the second correlation are most correlated and comparing the determined time value with a reference time value (e.g., determined at 306 of
The propagated signal may contain a predetermined signal and the predetermined signal is received at the various sensors. Each of the received signals is correlated with a reference signal to determine the results received at 602. In some embodiments, the received results are associated with a same signal content (e.g., same binary sequence) that has been freely propagated on a medium at the same time. In some embodiments, the received results are associated with different signal contents that have been disturbed by the same disturbance. In some embodiments, the received signal at a receiver/sensor includes components of a plurality of distinguishable signals transmitted by different transmitters and the received signal is separated into different received signals each corresponding to a transmitted signal of a signal transmitter for individual analysis to at least in part determine the results received at 602.
At 604, time differences associated with the plurality of results are used to determine a location associated with the disturbance. In some embodiments, each of the time differences is associated with a time when signals used in the correlation are most correlated. In some embodiments, the time differences are associated with a determined time delay/offset or phase difference caused on the received signal due to the disturbance. This time delay may be calculated by comparing a time value determined using a correlation with a reference time value that is associated with a scenario where a touch input has not been specified. The result of the comparison may be used to calculate a location of the disturbance relative to the locations of transmitters and/or sensors that received the plurality of signals. By using the location of the transmitters and/or sensors relative to a surface of a medium that has propagated the received signal, a location on the surface where the disturbance originated may be determined.
Although the foregoing embodiments have been described in some detail for purposes of clarity of understanding, the invention is not limited to the details provided. There are many alternative ways of implementing the invention. The disclosed embodiments are illustrative and not restrictive.
Claims
1. A system for detecting a location of a touch input, comprising:
- a plurality of transmitters coupled to a propagating medium and each configured to emit a signal that is distinguishable from other signals emitted from other transmitters, wherein the plurality of transmitters are configured to emit the distinguishable signals through the propagating medium such that at least a portion of each of the distinguishable signals emitted from the plurality of transmitters freely propagate directly through the propagating medium without being directly guided by a reflector and each of the distinguishable signals ultrasonically encodes different binary data from other of the distinguishable signals to distinguish each of the distinguishable signals from each other; and
- a receiver coupled to the propagating medium and configured to receive the signals from the transmitters to detect the location of the touch input on a surface of the propagating medium as indicated by an effect of the touch input on each of the distinguishable signals, wherein the receiver is configured to receive the signals from the transmitters at least in part by being configured to receive a combined signal that includes at least a portion of each of the distinguishable signals disturbed by the same touch input at the location, each of the distinguishable signals that ultrasonically encodes different binary data from other of the distinguishable signals have been separately transmitted by a different transmitter of the plurality of transmitters, and the receiver is configured to separate and provide as output, each of the included portions of the distinguishable signals from the received combined signal and the each of the included portions of the distinguishable signals that has been separated and provided as the output corresponds to a same single contact of the touch input provided at the same location.
2. The system of claim 1, wherein at least one of the received signals is correlated with a corresponding expected signal without the touch input to determine the effect of the touch input on the at least one received signal.
3. The system of claim 1, wherein the signals emitted by the transmitters are ultrasonic signals.
4. The system of claim 1, wherein the signals emitted by the transmitters are distinguishable from each other by varying a phase of the signals emitted by the transmitters from each other emitted signal.
5. The system of claim 1, wherein emitting the signals of the transmitters includes utilizing code division multiplexing to distinguish the emitted signals.
6. The system of claim 1, wherein the signals emitted by the transmitters are distinguishable from each other by varying a frequency range of the signals emitted by the transmitters from each other emitted signal.
7. The system of claim 1, wherein emitting the signals of the transmitters includes utilizing frequency division multiplexing to distinguish the emitted signals.
8. The system of claim 1, wherein the signals emitted by the transmitters are distinguishable from each other by varying a timing of the signals emitted by the transmitters from each other emitted signal.
9. The system of claim 1, wherein emitting the signals of the transmitters includes utilizing time division multiplexing to distinguish the emitted signals.
10. The system of claim 1, wherein emitting the signal that is distinguishable from other signals emitted from other transmitters includes offsetting the signal from the other signals emitted from other transmitters.
11. The system of claim 1, wherein emitting the signal that is distinguishable from other signals emitted from other transmitters includes offsetting a pseudorandom binary sequence included in the signal by a predetermined number of bits from a pseudorandom binary sequence included in the other signals emitted by other transmitters.
12. The system of claim 11, wherein a relative offset amount between a first signal and a second signal emitted by one or more of the transmitters is equal to a relative offset amount between the second signal and a third signal emitted by one or more of the transmitters.
13. The system of claim 1, wherein the signals emitted by the transmitters are orthogonal to each other signal.
14. The system of claim 1, wherein the effect of the touch input on each of the distinguishable signals includes a delay caused on each of the distinguishable signals by the touch input.
15. The system of claim 14, wherein detecting the location includes comparing the delay of each of the distinguishable signals.
16. The system of claim 1, wherein the touch input is associated with one of more of the following: a location coordinate, a gesture, a time, a status, a direction, a velocity, a force magnitude, a proximity, a pressure, and a size.
17. The system of claim 1, wherein the transmitters each includes a different transducer.
18. The system of claim 1, wherein at least one of the distinguishable signals includes a Zadoff-Chu sequence.
19. The system of claim 1, wherein detecting the location of the touch input includes comparing each of the separated distinguishable signals with a corresponding reference signal to determine comparison results and comparing one of the comparison results of one of the received distinguishable signals with another one of the comparison results of another one of the received distinguishable signals.
20. A method for detecting a location of a touch input, comprising:
- emitting from each of a plurality of transmitters coupled to a propagating medium a signal that is distinguishable from other signals emitted from other transmitters, wherein the distinguishable signals are emitted through the propagating medium such that at least a portion of each of the distinguishable signals emitted from the plurality of transmitters freely propagate directly through the propagating medium without being directly guided by a reflector and each of the distinguishable signals ultrasonically encodes different binary data from other of the distinguishable signals to distinguish each of the distinguishable signals from each other; and
- receiving from at least one receiver coupled to the propagating medium the signals from the transmitters to detect the location of the touch input on a surface of the propagating medium as indicated by an effect of the touch input on each of the distinguishable signals, wherein receiving the signals from the transmitters includes receiving a combined signal that includes at least a portion of each of the distinguishable signals disturbed by the same touch input at the location, each of the distinguishable signals that ultrasonically encodes different binary data from other of the distinguishable signals have been separately transmitted by a different transmitter of the plurality of transmitters, and separating and providing as output, each of the included portions of the distinguishable signals from the received combined signal, and the each of the included portions of the distinguishable signals that has been separated and provided as the output corresponds to a same single contact of the touch input provided at the same location.
21. A computer program product for detecting a location of a touch input, the computer program product being embodied in a non-transitory computer readable storage medium and comprising computer instructions for:
- emitting from each of a plurality of transmitters coupled to a propagating medium a signal that is distinguishable from other signals emitted from other transmitters, wherein the distinguishable signals are emitted through the propagating medium such that at least a portion of each of the distinguishable signals emitted from the plurality of transmitters freely propagate directly through the propagating medium without being directly guided by a reflector and each of the distinguishable signals ultrasonically encodes different binary data from other of the distinguishable signals to distinguish each of the distinguishable signals from each other; and
- receiving from at least one receiver coupled to the propagating medium the signals from the transmitters to detect the location of the touch input on a surface of the propagating medium as indicated by an effect of the touch input on each of the distinguishable signals, wherein receiving the signals from the transmitters includes receiving a combined signal that includes at least a portion of each of the distinguishable signals disturbed by the same touch input at the location, each of the distinguishable signals that ultrasonically encodes different binary data from other of the distinguishable signals have been separately transmitted by a different transmitter of the plurality of transmitters, and separating and providing as output, each of the included portions of the distinguishable signals from the received combined signal, and the each of the included portions of the distinguishable signals that has been separated and provided as the output corresponds to a same single contact of the touch input provided at the same location.
| 4488000 | December 11, 1984 | Glenn |
| 5334805 | August 2, 1994 | Knowles et al. |
| 5451723 | September 19, 1995 | Huang et al. |
| 5563849 | October 8, 1996 | Hall et al. |
| 5573077 | November 12, 1996 | Knowles |
| 5637839 | June 10, 1997 | Yamaguchi et al. |
| 5708460 | January 13, 1998 | Young et al. |
| 5739479 | April 14, 1998 | Davis-Cannon et al. |
| 5784054 | July 21, 1998 | Armstrong et al. |
| 5883457 | March 16, 1999 | Rinde et al. |
| 5912659 | June 15, 1999 | Rutledge et al. |
| 6091406 | July 18, 2000 | Kambara et al. |
| 6232960 | May 15, 2001 | Goldman |
| 6254105 | July 3, 2001 | Rinde et al. |
| 6473075 | October 29, 2002 | Gomes et al. |
| 6492979 | December 10, 2002 | Kent et al. |
| 6535147 | March 18, 2003 | Masters et al. |
| 6567077 | May 20, 2003 | Inoue et al. |
| 6630929 | October 7, 2003 | Adler et al. |
| 6633280 | October 14, 2003 | Matsumoto et al. |
| 6636201 | October 21, 2003 | Gomes et al. |
| 6788296 | September 7, 2004 | Ikeda et al. |
| 6798403 | September 28, 2004 | Kitada et al. |
| 6856259 | February 15, 2005 | Sharp |
| 6891527 | May 10, 2005 | Chapman et al. |
| 6948371 | September 27, 2005 | Tanaka et al. |
| 7000474 | February 21, 2006 | Kent |
| 7006081 | February 28, 2006 | Kent et al. |
| 7116315 | October 3, 2006 | Sharp et al. |
| 7119800 | October 10, 2006 | Kent et al. |
| 7187369 | March 6, 2007 | Kanbara et al. |
| 7193617 | March 20, 2007 | Kanbara et al. |
| 7204148 | April 17, 2007 | Tanaka et al. |
| 7218248 | May 15, 2007 | Kong et al. |
| 7274358 | September 25, 2007 | Kent |
| RE39881 | October 16, 2007 | Flowers |
| 7315336 | January 1, 2008 | North et al. |
| 7345677 | March 18, 2008 | Ing et al. |
| 7411581 | August 12, 2008 | Hardie-Bick |
| 7456825 | November 25, 2008 | Kent et al. |
| 7511711 | March 31, 2009 | Ing et al. |
| 7545365 | June 9, 2009 | Kent et al. |
| 7554246 | June 30, 2009 | Maruyama et al. |
| 7583255 | September 1, 2009 | Ing |
| 7649807 | January 19, 2010 | Ing |
| 7683894 | March 23, 2010 | Kent |
| 7880721 | February 1, 2011 | Suzuki |
| 7920133 | April 5, 2011 | Tsumura et al. |
| 8085124 | December 27, 2011 | Ing |
| 8228121 | July 24, 2012 | Benhamouda et al. |
| 8237676 | August 7, 2012 | Duheille et al. |
| 8319752 | November 27, 2012 | Hardie-Bick |
| 8325159 | December 4, 2012 | Kent et al. |
| 8358277 | January 22, 2013 | Mosby et al. |
| 8378974 | February 19, 2013 | Aroyan et al. |
| 8392486 | March 5, 2013 | Ing |
| 8427423 | April 23, 2013 | Tsumura |
| 8436806 | May 7, 2013 | Almalki et al. |
| 8436808 | May 7, 2013 | Chapman et al. |
| 8493332 | July 23, 2013 | D'Souza |
| 8576202 | November 5, 2013 | Tanaka et al. |
| 8619063 | December 31, 2013 | Chaine et al. |
| 8638318 | January 28, 2014 | Gao et al. |
| 8648815 | February 11, 2014 | Kent et al. |
| 8659579 | February 25, 2014 | Nadjar et al. |
| 8670290 | March 11, 2014 | Aklil et al. |
| 8681128 | March 25, 2014 | Scharff et al. |
| 8692809 | April 8, 2014 | D'Souza |
| 8692810 | April 8, 2014 | Ing |
| 8692812 | April 8, 2014 | Hecht |
| 8730213 | May 20, 2014 | D'Souza et al. |
| 8749517 | June 10, 2014 | Aklil |
| 8823685 | September 2, 2014 | Scharff et al. |
| 8854339 | October 7, 2014 | Kent et al. |
| 8890852 | November 18, 2014 | Aroyan et al. |
| 8896429 | November 25, 2014 | Chaine |
| 8896564 | November 25, 2014 | Scharff et al. |
| 8917249 | December 23, 2014 | Buuck et al. |
| 8941624 | January 27, 2015 | Kent et al. |
| 8946973 | February 3, 2015 | Pelletier |
| 8994696 | March 31, 2015 | Berget et al. |
| 9030436 | May 12, 2015 | Ikeda |
| 9046959 | June 2, 2015 | Schevin et al. |
| 9046966 | June 2, 2015 | D'Souza |
| 9058071 | June 16, 2015 | Esteve |
| 9099971 | August 4, 2015 | Lynn et al. |
| 20010050677 | December 13, 2001 | Tosaya |
| 20020185981 | December 12, 2002 | Dietz et al. |
| 20030197691 | October 23, 2003 | Fujiwara |
| 20030206162 | November 6, 2003 | Roberts |
| 20040133366 | July 8, 2004 | Sullivan |
| 20040160421 | August 19, 2004 | Sullivan |
| 20040183788 | September 23, 2004 | Kurashima et al. |
| 20040239649 | December 2, 2004 | Ludtke |
| 20040246239 | December 9, 2004 | Knowles et al. |
| 20060071912 | April 6, 2006 | Hill et al. |
| 20060114233 | June 1, 2006 | Radivojevic et al. |
| 20060139340 | June 29, 2006 | Geaghan |
| 20060166681 | July 27, 2006 | Lohbihler |
| 20060262104 | November 23, 2006 | Sullivan et al. |
| 20070109274 | May 17, 2007 | Reynolds |
| 20070165009 | July 19, 2007 | Sakurai et al. |
| 20070171212 | July 26, 2007 | Sakurai et al. |
| 20070211022 | September 13, 2007 | Boillot |
| 20070214462 | September 13, 2007 | Boillot |
| 20070229479 | October 4, 2007 | Choo et al. |
| 20070279398 | December 6, 2007 | Tsumura et al. |
| 20080018618 | January 24, 2008 | Hill et al. |
| 20080030479 | February 7, 2008 | Lowles et al. |
| 20080081671 | April 3, 2008 | Wang et al. |
| 20080105470 | May 8, 2008 | Van De Ven et al. |
| 20080111788 | May 15, 2008 | Rosenberg et al. |
| 20080174565 | July 24, 2008 | Chang et al. |
| 20080198145 | August 21, 2008 | Knowles et al. |
| 20080231612 | September 25, 2008 | Hill et al. |
| 20080284755 | November 20, 2008 | Hardie-Bick |
| 20090103853 | April 23, 2009 | Daniel |
| 20090146533 | June 11, 2009 | Leskinen et al. |
| 20090160728 | June 25, 2009 | Emrick et al. |
| 20090167704 | July 2, 2009 | Terlizzi et al. |
| 20090237372 | September 24, 2009 | Kim et al. |
| 20090271004 | October 29, 2009 | Zecchin et al. |
| 20090273583 | November 5, 2009 | Norhammar |
| 20090315848 | December 24, 2009 | Ku et al. |
| 20100026667 | February 4, 2010 | Bernstein |
| 20100044121 | February 25, 2010 | Simon et al. |
| 20100045635 | February 25, 2010 | Soo |
| 20100079264 | April 1, 2010 | Hoellwarth |
| 20100117993 | May 13, 2010 | Kent |
| 20100156818 | June 24, 2010 | Burrough et al. |
| 20100165215 | July 1, 2010 | Shim |
| 20100185989 | July 22, 2010 | Shiplacoff et al. |
| 20100188356 | July 29, 2010 | Vu et al. |
| 20100245265 | September 30, 2010 | Sato et al. |
| 20100269040 | October 21, 2010 | Lee |
| 20100277431 | November 4, 2010 | Klinghult |
| 20100315373 | December 16, 2010 | Steinhauser et al. |
| 20100321312 | December 23, 2010 | Han et al. |
| 20100321325 | December 23, 2010 | Springer et al. |
| 20100321337 | December 23, 2010 | Liao et al. |
| 20110012717 | January 20, 2011 | Pance et al. |
| 20110018695 | January 27, 2011 | Bells et al. |
| 20110042152 | February 24, 2011 | Wu |
| 20110057903 | March 10, 2011 | Yamano et al. |
| 20110063228 | March 17, 2011 | St. Pierre |
| 20110080350 | April 7, 2011 | Almalki et al. |
| 20110084912 | April 14, 2011 | Almalki |
| 20110156967 | June 30, 2011 | Oh et al. |
| 20110167391 | July 7, 2011 | Momeyer et al. |
| 20110175813 | July 21, 2011 | Sarwar et al. |
| 20110199342 | August 18, 2011 | Vartanian |
| 20110260990 | October 27, 2011 | Ali et al. |
| 20110298670 | December 8, 2011 | Jung et al. |
| 20110316790 | December 29, 2011 | Ollila et al. |
| 20120001875 | January 5, 2012 | Li et al. |
| 20120026114 | February 2, 2012 | Lee et al. |
| 20120050230 | March 1, 2012 | Harris |
| 20120062564 | March 15, 2012 | Miyashita et al. |
| 20120068939 | March 22, 2012 | Pemberton-Pigott |
| 20120068970 | March 22, 2012 | Pemberton-Pigott |
| 20120081337 | April 5, 2012 | Camp et al. |
| 20120088548 | April 12, 2012 | Yun et al. |
| 20120120031 | May 17, 2012 | Thuillier |
| 20120126962 | May 24, 2012 | Ujii et al. |
| 20120127088 | May 24, 2012 | Pance et al. |
| 20120188889 | July 26, 2012 | Sambhwani et al. |
| 20120194466 | August 2, 2012 | Posamentier |
| 20120200517 | August 9, 2012 | Nikolovski |
| 20120229407 | September 13, 2012 | Harris et al. |
| 20120232834 | September 13, 2012 | Roche et al. |
| 20120272089 | October 25, 2012 | Hatfield et al. |
| 20130059532 | March 7, 2013 | Mahanfar et al. |
| 20130249831 | September 26, 2013 | Harris |
| 20140185834 | July 3, 2014 | Fromel et al. |
| 101373415 | February 2009 | CN |
| 101669088 | March 2010 | CN |
| 2948787 | February 2011 | FR |
| 1020040017272 | February 2004 | KR |
| 1020050092179 | February 2004 | KR |
| 1020070005580 | January 2007 | KR |
| 1020080005990 | January 2008 | KR |
| 2006115947 | November 2006 | WO |
| 2006115947 | November 2006 | WO |
| 2011010037 | January 2011 | WO |
| 2011024434 | March 2011 | WO |
| 2011048433 | April 2011 | WO |
| 2011051722 | May 2011 | WO |
| 2012010912 | January 2012 | WO |
- Liu et al., “Acoustic Wave Approach for Multi-Touch Tactile Sensing”, Micro-NanoMechatronics and Human Science, 2009. MHS 2009. International Symposium, Nov. 9-11, 2009.
Type: Grant
Filed: Sep 20, 2013
Date of Patent: May 2, 2017
Patent Publication Number: 20140078112
Assignee: Sentons Inc. (Cayman Islands)
Inventors: Samuel W. Sheng (Saratoga, CA), Shih-Ming Shih (San Jose, CA), Yenyu Hsieh (San Jose, CA), Shirish A. Altekar (Palo Alto, CA)
Primary Examiner: Kent Chang
Assistant Examiner: Sujit Shah
Application Number: 14/033,316
International Classification: G06F 3/043 (20060101);
